Button 2 Operations

Button 2 a is usually the center button on a three-button pointing
device. On two-button mice, the right button is typically button 3,
and button 2 is missing. On some systems, pressing buttons 1 and 3
simultaneously will simulate a button 2 press. Xic provides
alternative ways to perform the button 2 operations, so that a
two-button pointing device can be used, but is a tiny bit less
efficient.

If button 2 is clicked in a drawing window, the window is redrawn with
the click location centered in the window. If instead button 2 is
pressed and the pointer moved to a new location before release, the
window is redrawn with the press location moved to the release
location. If there are multiple windows open, only the window under
the release will be redrawn. Thus, for example to change the view in
a sub-window, press and hold button 2 while pointing at the desired
feature in the main (or another) window, then release button 2 while
pointing in the sub-window. The sub-window will show the pointed-to
objects at the release location.

The same action will be initiated if button 3 is pressed while either
the Shift or Ctrl key is held down. The key state when
button 3 is released does not matter.

In the layer menu, button 2 will switch the visibility of layers, as
indicated by the sample box. Clicking button 2 on the individual
layers toggles their visibility. Clicking button 2 on the small box
icon at the far right of the layer menu will toggle visibility of all
layers. All layers will be set to visible or invisible according to
whether a majority of layers were originally invisible or visible,
respectively.

The behavior is a little different between physical and electrical
modes. In physical mode, the screen will not be redrawn
automatically, unless the Shift key is held during the button 2
press, but can be redrawn by clicking button 2 in the center of the
drawing window, or by pressing the Ctrl-r key combination.

In electrical mode, the screen is automatically redrawn. The SCED
(drawing) layer is always visible. Instead of the visibility of this
layer being toggled, the fill setting is toggled between solid and
empty fill.

The same behavior is obtained by holding Shift or Ctrl
while clicking with button 1 in the layer menu. If Shift is
held, the screen will be redrawn automatically while in physical
mode.